Dear Energy Professional, Dear Colleagues
This coal mine, which produces the coal requirements of the Kangal Thermal Power Plant (457 MWe) is located 30 km south of Kangal (Sivas) city center. Coal mine site is licensed to Public Electric Generation Company, and it has been operated by a local private contracting company since 1989 under a 20-year long term agreement.
At the Kalburçayırı section, coal production is still continued in two seams, each at 7 meters thickness on average, the overburden thickness is 42 meters above seam and interburden thickness is 20 meters between seams. The stripping amount of the overburden and interburden is approximately 30m tons per year, for an annual coal production of 6m tons to meet the fuel demands of the Kangal mine mouth thermal power plant.
In Kangal (Sivas) thermal power plant, there is an ongoing rehabilitation order as placed by the Public Electricity Generation Company to the OEM supplier without any competitive tender. We sincerely feel that order- without competitive tender is not a correct decision.
During early construction of the power plant in some years past (1990-1991), we all know that the OEM Company had made many designs, fabrication and operational faults. They were unsolved during commissioning then and hence we had a fast worn-out plant.
Now rehabilitation is unavoidable for smooth, full and efficient operation, and the owner public company had placed order to the original equipment supplier, although their failure was apparent as proven in the past operation.
In this case during rehabilitation, we now observed that the first unit with design capacity at 150 MWe maximum continuous rate (MCR), had not reached the expected capacity but generated only 135 MWe for more than one month.
We have doubts in capacity design and selection of Forced draft fans, induced draft fan, their flow control mechanisms, safety valves, soot blower selections. Fans were oversized, other equipment were undersized in the original design.
We strongly advocate and recommend the Public owner company to hire a local experienced engineering company as the independent owner’s engineer company to monitor, control the rehabilitation order and also make the complete design check prior to and during the whole project execution period.
Kangal thermal plant is in the Sivas province at a far distance where we all forget but expect the plant to generate 3 each 150 MWe electricity for the national grid. We all know that there is a coal supply fraud case in the nearby coal premises whish is still in the local court to be resolved.
It is released that Hungarian by Transelectro and German Siemens companies jointly received the rehabilitation order. The temporary acceptance procedure of the first unit is scheduled to start on 5th October 2009. The second unit rehabilitation is already started. Project execution is expected to be completed in year 2010. Contract was signed in year 2006, for 56.5m Euros. State Planning Organization has allocated 130.2 million TL budget for the overall rehabilitation of the plant. In year 2010, 25 million TL will be spent within that budget. This money is public money. We all have our shares and contributions for the overhaul of the aging thermal power plant. Therefore we have serious questions on the execution of the ongoing rehabilitation work at site,
- We need to know if the owner company has any independent owners engineer company to monitor and control rehabilitation order. Do we have any design check by an independent engineering company prior and during rehabilitation work?
- We need to if the steam boilers are cleaned by pressurized water completely. This procedure is unknown in the local market, but this is common practice in the US power plants in rehabilitation scheme. By water cleaning, you can better locate the wears and tears, and defect equipment.
- We need to know the number of soot blowers (48 each per boiler?), their soot blowing capacities, if their capacities are increased, if they are replaced with new equipment. We know that the original soot blowers were undersized, less in number than required, and hence unable to clean the soots during full load.
- We need to know the names of soot blower suppliers, are they well known international proven brands, or poor quality unknown brands? We need to know if rotary or retractable soot blowers are preferred.
- We need to know if all safety valves are replaced with better capacity new units. We need to know if the new safety valves have better and shorter response time for overpressure to open up to protect the pressured tube walls.
- We need to know if the roof tube walls have proper expansion details during high loads in operation. If they do knot have these expansion compensation details then the walls will be seriously bended or even crashed during operation.
- We need to know the number of fuel oil burners in supplementary firing (originally 6 each per boiler at 2500 kg/hr capacity)? How many burners we have now after rehabilitation, what is their oil burner capacity each? What is their turndown ration?
- We need to know if we can fire the incoming local lignite without any supplementary firing, which is the desirable condition during full loading.
- We need to know if they had any calorific value enrichment of the available coal prior to feeding to coal mills (>990- 1210 kcal/kg LHV, 48% water, 23% ash average). Any mechanical selection and/or water floating?
- We need to know what has been done to upgrade the coal mills (6 each per boiler?)
- We need to know if electrostatic precipitations are replaced with new ones, we know that the original E/P's were undersized and unable to collect the fly ash during operation.
- We need to know the spec details of forced draft fans and induced draft fans, if they work properly during operation, if their air and gas flow control valves can control the operation properly.
- Do we have flue gas desulphurization system in proper continuous operation in the plant? What is the sulphur content in the incoming coal (avg. >1.93%)?
- We need to know if instrumentation and control systems are replaced with new computer controlled internationally approved brands
- We need to know if the high voltage switchyard has been upgrade high voltage transmission lines are overhauled.
- Original Steam turbines were manufactured by Mitsubishi of Japan. So what is the scope of Siemens of Germany in the rehabilitation? What is the reasoning behind this?
We, the local engineers in Chambers of Turkish engineers in Mechanical, Mining, Chemical, Electrical engineering disciplines would be pleased to join in a workshop meeting at the site in near future in order to evaluate the ongoing rehabilitation works and review the site activities. We feel that this is our public responsibility.
We have general elections for the upper management of the Chambers in January- February 2010; therefore the best timing for such a workshop organization in Kangal thermal power plant could be in April- May 2010.
Likewise Sivas Cumhuriyet University, or Kangal power plant administration, or their upper management in the Public Electricity Company may organize such workshop at the site, invites us to the plant and then we all comply with the invitation and participate to put our engineering contributions for the best interest of our national wealth.
Your comments are always welcome
Haluk Direskeneli, Ankara-based independent Energy Analyst